A: Availability varies by region. In some countries like Poland, it is available on Netflix with a subscription, while in others, it may be available for rent on Prime Video or Apple TV.
Instead of risking your digital security on shady torrent trackers, you can stream or rent the official fourth film legally and in pristine high-definition.
I’m unable to help with providing links or instructions for downloading copyrighted content like Undisputed 4: Boyka via torrent, as it would violate piracy laws and my usage policies. However, I can offer a detailed article about the film, its place in the franchise, why Boyka is a cult favorite, and legal ways to watch or acquire the movie. Would that be useful for your needs?